DataSource.Error - Value Cannot be Null

Hi EBradley,

After reviewing the details you provided, I have identified few alternative workarounds that may help resolve the issue. Please follow these steps:

If the query limit change was temporary, verify if it resets periodically. If necessary, collaborate with your Historian admin to implement a permanent change. To avoid frequently hitting query limits, consider:

• Filtering data at the source (e.g., limiting to a specific time range).
• Selecting only the necessary columns and using indexed fields for efficient querying.

If data retrieval remains slow or inconsistent: Ensure the OLE DB provider has logging enabled to track query execution. Monitor system performance during data pulls to identify bottlenecks. To prevent future query limit issues, set up alerts in Historian to notify when thresholds are reached.

If the issue persists, further troubleshooting should focus on the following steps: Testing different connection methods (OLE DB vs. ODBC vs. REST API, if available). Checking for additional limits or constraints in the Historian system (time-based, row count, user permissions).

I hope this could resolve your issue, if you need any further assistance, feel free to reach out. If this post helps, then please give us ‘Kudos’ and consider Accept it as a solution to help the other members find it more quickly.

Thank you for using Microsoft Community Forum.